Walt Disney himself had a lot of input and say on a number of the original attractions that made up the Magic Kingdom park when it was built. One of those original attractions is Jungle Cruise, and because it's an original and was one of Walt's personal favorites, some feel it should simply always be in service and never touched as in replaced or updated. I can understand that view, as there is so much progress and new things coming all throughout Disney World that it may seem like the old favorites will be lost forever in the shuffle.
Personally, I'm not one of those "some" who feel this is a great attraction and shouldn't be touched. I've ridden it when I was young, and I've ridden it when I was older and I've never considered it more than a "mehh" attraction at best. I'm of the opinion that the day for this attraction is long since over and it should be retired into that old book of remembrance of Disney attractions of days past. Time to look to the present and future and use the space here for something new that's actually interesting and enjoyable.
If unfamiliar with this attraction, it is a boat ride located in the Adventureland area of the Magic Kingdom. Its theme or story is that your boat skipper is taking your all on a leisurely boat ride along four of the world's most famous rivers: South America's Amazon, Africa's Congo, Egypt's Nile, and Cambodia's Mekong. Along the way you come into close contact with a number of exotic animals: pythons, hippos, elephants, crocodiles, gorillas, lions, and so forth. You also come in contact with some of the savage headhunters of the area. This slow-moving boat ride also takes you behind waterfalls and through ancient temple ruins before bringing you right back where you started.
*** NOTE: When you come upon the half of a plane during your cruise....if you're wondering where the other half is, just check out the Casablanca scene in the Great Movie Ride over at the Hollywood Studios park.
In and of itself, the ride is a harmless, non-exciting tranquil little boat excursion that the small, small children may get a lot of enjoyment out of, but most adults would probably find incredibly boring. (Although, it does get a little dark and possibly frightening for those little ones when the boat briefly goes through the temple scene.) Some of my issues with the ride is that it appears none of the animatronics have been updated at all and there are much better animatronics in other attractions in the park. Why not try and improve them here? Also, your skipper - try as they all do - cracks some of the most unfunny puns all throughout, which tended to get a little annoying (especially so since if you ride several times with different skippers, they tend to just use the same jokes again and again).
Don't get me wrong, however, I'd say it is worth at least ONE ride to see what it's like and to see that you're not missing anything here. It still is a popular attraction, one that even has Fastpass machines for it. But again, I don't care for this attraction, and the fact that it is still somewhat popular tends to work to my advantage because it keeps those people off the lines of the other rides I really enjoy.